Upgrade grpc to v1.53.0, as preparation for introducing OpenTelemetry,
which depends on that grpc version.
Two changes to our own code were necessitated by upstream changes:
1. Add a stub implementation of GetOrBuildProducer: this was added to
the balancer.SubConn interface by grpc v1.51.0
2. Change use of Endpoint field to Endpoint() method: the field was
removed and replaced by a method in
https://github.com/grpc/grpc-go/pull/5852. This also means that our
tests can't set the .Endpoint field, so the tests are updated to use the
.URL field instead, and a helper has been added to make that easy.
Part of #6361
- Fork the default `dns` resolver from `go-grpc` to add backend discovery via
DNS SRV resource records.
- Add new fields for SRV based discovery to `cmd.GRPCClientConfig`
- Add new (optional) field `DNSAuthority` for specifying custom DNS server to
`cmd.GRPCClientConfig`
- Add a utility method to `cmd.GRPCClientConfig` to simplify target URI and host
construction. With three schemes and `DNSAuthority` it makes more sense to
handle all of this parsing and construction outside of the RPC client
constructor.
Resolves#6111
Matthew McPherrin
Samantha